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New Member

Is Cef required on MQC-Based Frame Relay Traffic Shaping

From http://www.cisco.com/en/US/tech/tk39/tk824/technologies_tech_note09186a0080094978.shtml#topic2

The MQC-Based Frame Relay Traffic Shaping feature allows the configuration of FRTS with the help of Modular QoS CLI commands. CEF must be enabled for this feature to be configured (for routers in the Cisco 7500 and later product range, dCEF is required). For more information about this feature and its prerequisites, refer to MQC-Based Frame Relay Traffic Shaping.

I am correct to say that, CEF is required on 3600 and 2600 platform to have a working MQC-Based Frame Relay Traffic Shaping.

Thanks

4 REPLIES
New Member

Re: Is Cef required on MQC-Based Frame Relay Traffic Shaping

I'm going to have to say that it is incorrect. I read further into the article and the only thing I could find...

For FRTS using MQC for the routers specified in the "Supported Platforms" section, distributed Cisco Express Forwarding (dCEF) is not required. For FRTS using MQC for routers in the Cisco 7500 and above product range, dCEF is required.

I looked further on the DocCD and couldn't find anything to back this up as well. CEF is generally enabled by default in newer code anyway so unless your working on 7500+ series routers I wouldn't worry about it, if so then you need to look into enabling dCEF.

New Member

Re: Is Cef required on MQC-Based Frame Relay Traffic Shaping

I wouldn't worry about 7500 since i would enable dcef. The cco doc is clear about it.

I would like dcef to be enabled also since it lessens cpu util.

The reason i ask this question because i have a c2600 and c3600 on frame-relay link which is configured for FRTS and MQC.

I am pretty sure configs is not a problem. "show frame pvc xxx" shows that the priority traffic counters are having hits with 0 priority drops. However during congestion it seems that our reserved bandwidth for priority didn't work at all. Still output shows 0 drops on priority.

I enabled debug priority hoping to see any output for any possible drops on priority but nothing. not even output that packets are being prioritized is seen. i enabled "term mon" of course since i was using telnet.

Only thing i noticed was ip cef since it is not enabled on both routers. This is the reason i wanted to verify if cef is needed.

it could be due to this or a ddts since our ios code is really old 12.2(a reason for me not to enable cef...too buggy on this code.)

policing however did work with FRTS. But the most important thing is the priority and not policing.

any ideas?

Re: Is Cef required on MQC-Based Frame Relay Traffic Shaping

I believe you do need CEF.

And how "bad" would be to enable CEF on these routers?

I thought it was always recommended to have CEF on the routers.

Vlad

"The MQC-Based Frame Relay Traffic Shaping feature allows the configuration of FRTS with the help of Modular QoS CLI commands. CEF must be enabled for this feature to be configured"

New Member

Re: Is Cef required on MQC-Based Frame Relay Traffic Shaping

how bad? ...usally causes router crash, unexpected reload, etc.

I've seen a lot of ddts concerning cef on old ios and experienced it as well. Specially for the deferred image that we are using. :-) (Don't ask me why we use a deferred image. lol) For 12.3 image, i'd say go for cef.

But since i need to have the QoS working, it seems have to try and hopefully no problems.

Thank you.

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